Magnetically coupled governor



May 23, 1950 A. N. NILSON MAGNETICALLY COUPLED GOVERNOR Filed July 8, 1948 INVENTOR ARTHUR N. NILSON ATTORNEY oom momnow mw oa Patented May 23, 1950 MAGNETICALLY COUPLED GOVERNOR Arthur N. Nilson, Chicago, 111., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application July 8, 1948, Serial No. 37,621

7 Claims.

This invention relates :to governors and more articularly to magnetically coupled governors for electrical apparatus.

An object of the invention is to provide an improved governor of simple design and construotion which is particularly effective in co trolling the speed of the driving motors of printing telegraph apparatus.

In the field of printing telegraphy it is of utmost importanc that the transmitting and receiv-ing apparatus be driven at the same rates of sp ed. .In o der to accomplish this it is most desirable that thespeed-of all the power devices in the telegraph system be maintained at a single constant speed. Accordinglydt is another object of the invention to provide a governor capable of maintaining the speed of rotation of an electric motor subs antially (con tant.

A further object of the invention is to provide a governor which will operate with a minimum of friction and noise. Another object of the invention is to provide a governor which is readily adjustable in order to make it possible to vary the constant speed at which the motor-is retained.

Another object of the invention is to provide a overn r whereina controlling member is p itioned at leastlonce during each revolution thereof solely by centritugal force and during another portion of the revolution, the member, having been positioned by centrifugal force, is attracted towards onemagnet or another to retain a switch in the motor circuit :in either open or closed disc I8.

position during the remainder of the revolution.

Th s and other objects and advanta es of the nv n i n will beapparent fr m he f owin tailed description-of the invention when read in con unction with the -aooomnanying drawing in which,

of a bushing IS. A bracket 2| is firmly secured to the disc l8 and a stiff leaf spring 22 is secured to the bracket 2| by means of a bolt 23. An arm is riveted to the leaf spring '22 and carries a motivating shoe 26. The arm 24 is movable pivotally slightly with the leaf spring 22 serving as a fulcrum, however, its movement is restrained by a pair of limiting stops 21. The arm 24 carries a contact point 28 which is adapted to cooperate with an adjustable contact point as carried by a bracket 3| suitably secured to the disc 58. The leaf spring 22 is insulated from the disc I8 and is electrically connected by means (not shown) to a brush 32 which rides the collector ring It. The contact point 29 is suitably insulated from the disc 18 and is electrically connected (also by means not shown) to a brush 33 which rides the collector ring ll. It is therefore apparent when the contact points 23 and 29 are closed that a circuit is established to the motor which is being governed. This circuit is the power circuit to the motor.

A bracket 34 is secured to the disc l8 and has an aperture 36 therethrough within'which a bolt 3.! is slidable. The bolt 31 has a flattened portion 38 which is slidable and guided in an aperture 39 of a bracket 4| suitably secured to the A tension spring 42 connects the bolt 31 to the arm 24 and the force of the spring 42 urging the arm 24 towards the center of the disc 1! 8, or counterclockwise in Fig. 2 is readily adjustable by means of a nut 43 threaded to the bolt 31.

A magnet 44 is mounted securely to the casing l3 by means of a bolt 46 and secured to opposite ends of the magnet 44 are a pair of pole pieces i and 48. Each of the pole pieces 4'! and 48 is in the form of a disc having an inner cylindri- Fig. 1 is aside elevational sectional view of the I governor forming the subject matter of the invacuum, and

Fig. 2 is a iron}; elevational view.

Re r n to t e draw ng, reference numeral H fers to a rotatable power shaft and a pla [2 is secured to aonotor (repnesented only by a c mmuta or :9 and: brushes 10 the sp d of wh ch it is desir d o overn A. casing 3 is sui ab y cured o. the plate '12.. o provide a housing for the governor mechanism. An insulator ring I4, made of any suitable insulating material, is secured to the plate .22 and supports a pair oi colle tor. rings, .115 and. ill it lead M extends from a power source to the collector ring It, a lead 203 extends from the collector ring I! to one of the brushes It, and a lead 200 extends from the other brush I!) to the 126.21? i pui f A disc I8 is secured to the shaft H by means cal segmental ring 49 and an outer cylindrical segmental ring 5|. Each of the pole pieces 41 and 48 also have coadjacent cut out portions 52. The motivating shoe 2-6 is movable between the cylindrical rings 49 and 5| and the stops 2'! are so positioned that the shoe 26 cannot engage either of the rings 49 or 5|. The magnetic attractive force of the rings 49 and 5| for the shoe 2c is substantially the same for each ring and therefore while the shoe 26 is in a position between the rings it will be attracted towards the ring which it is nearer.

In the following description of the operation of the governor it is assumed that the motor shaft H is at rest. of the spring 42 is urging the, arm 24 inwardly so that the contacts '28 and 29 are closed. Therefore, when the main switch (not shown) in the motor circuit. is closed, current is established to the motor.

At this time the entire force As the motor, after being started, gains speed, centrifugal force acts on the motivating shoe 26 in a direction opposite to the force of the spring 42. During each revolution of the disc l8 and shoe 26, the shoe 26 is positioned solely by the balance of centrifugal force and the force of the spring 42 as the shoe passes the cut out portions 52 in the pole pieces 41 and 48. As the shaft II and disc l8 are accelerating to the proper speed the force of the spring 42 is stronger than the centrifugal force acting on the shoe 26 and arm 24, so that as the shoe leaves the cut out portions and enters the space between the rings 49 and it is closer to the ring 49. Therefore, during that revolution the ring 49 attracts the shoe 25 to thereby retain the contacts 28 and 29 in closed relation for the remainder of that revolution. Upon the shaft H reaching the desired constant speed of rotation, centrifugal force operating on the shoe 26, while it travels in the cut out portion 52, is sufiicient to move the shoe 26 outwardly so that upon entering the space between the rings 49 and 50, the shoe is nearer to the ring 5i. Therefore, the force of magnetic attraction of the ring 5| on the shoe 26 is greater than that of the ring 49, so that the contacts 28 and 29 are retained in disengaged relation for the remainder of that particular revolution of the disc I8 and shoe 26.

The magnetic forces of attraction of both of the rings 49 and 50 are substantially equal and therefore the shoe 2B is attracted towards the ring which the shoe is nearer upon leaving the cut out portion 52 during each revolution. Only a slight variation in the speed of rotation of the disc I8 is necessary in order to enable the cen trifugal force to move the shoe 2S sufficiently that the opposing magnetic ring 49 or 50 becomes effective.

Obviously, as the main motor switch is opened when it is desired to shut off the motor, during the deceleration of the shaft H, the centrifugal force of rotation decreases so that the contacts 28 and 29 are retained closed. The circuit to the motor therefore is always in condition to start the motor whenever the main motor switch is closed subsequently.

It will be understood that the embodiment of the invention shown and described is merely illustrative of the principles involved and numerous modifications and changes may be made without departing from the spirit of the invention.

What is claimed is:

1. In a control device for electrical apparatus having an electrical power circuit, a centrifugally and magnetically positionable member, a first magnetic means for attracting said member to cause a closure of said power circuit, and second magnetic means for attracting said member to cause a break in said power circuit, the effectiveness of each of said magnetic means being determined in accordance with the positionment of said member by centrifugal force.

2. In a governor for electric motors, a member positionable by centrifugal force at least once during each revolution of the motor shaft, a first magnetic means for attracting said member to cause a closure of a power circuit to the motor, and a second magnetic means for attracting said member to cause a break in the power circuit, the effectiveness of each of said magnetic means being determined in accordance with the positionment of said member by centrifugal force.

3. In a governor for an electric motor, a power circuit to the motor, a switch in said power circuit, a movable member for controlling the operation of said switch, said member being positioned at least once during each revolution of the motor shaft by centrifugal force, a first magnetic means for attracting said member to cause a closure of said switch, and a second magnetic means for attracting said member to cause an opening of said switch, the effectiveness of each of said magnetic means being determined in accordance with the positionment of said member by centrifugal force.

4. In a control apparatus for power devices, a movable member for controlling the power supply to the power device, said member being positioned by centrifugal force during a portion of each revolution of the power device, a motivating shoe on the movable member responsive to magnetic forces, and a pair of segmental magnetic rings between which said motivating shoe is designed to rotate, said centrifugal force being effective to position said shoe nearer to one of said rings than to the other whereupon the nearer ring is effective to attract said shoe and thereby control the power supply during the remainder of that revolution.

5. In a governor for electrical apparatus, a rotatable motivating shoe, a switch in the circuit of the electrical apparatus operable in accordance with the radial positionment of said shoe relative to its axis of rotation, and a plurality of concentric cylindrically shaped magnets having coadjacent cut out portions therein, said shoe being adapted to rotate between said magnets and to be positioned solely by centrifugal force when rotating in said coadjacent cut out portions, a group of said magnets as determined by the centrifugal positionment of said shoe being effective upon the entry of said shoe between said magnets to attract said shoe and thereby control said switch during the remainder of that revolution of said shoe.

6. In a governor for electrical apparatus, a pair of relatively movable contacts, centrifugally responsive means for controlling the relative positions of said contacts at least once during each revolution of a power shaft of the electrical apparatus, and magnetic means effective during the remainder of each revolution for maintaining said contacts in open or closed relation according to the relative positions of said contacts as determined by said centrifugally responsive means.

7. In a governor for electrical apparatus, a pair of relatively movable contacts, centrifugally responsive means for controlling the relative positions of said contacts at least once during each revolution of a power shaft of the electrical apparatus, a first magnetic means capable during the remainder of each revolution to maintain said contacts in open relation, and a second magnetic means capable during the remainder of each revolution to maintain said contacts in closed relation, the effectiveness of either of said magnetic means being dependent upon the relative positions of said contacts as determined each revolution by said centrifugally responsive means.

ARTHUR N. NILSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,918,203 Wise July 11, 1933 

